Basic ecological information is lacking for most caecilian amphibian populations, especially those of the Neotropical region where only few and nonquantitative ecological data were obtained for a small number of species. The Neotropical genus Caecilia is the most diverse of Gymnophiona with 33 species, for which natural history information is restricted to the description of clutch size for just one species. We provide natural history data based on 61 specimens of Caecilia gracilis found in a riparian forest in Cerrado biome in northeastern Brazil. No sexual dimorphism was found in morphometric and meristic data analyzed, probably because of functional constraints related to subterranean life. No specimens were found in the dry season, but in the wet season they were found at soil depth ranging from 5 to 31.5 cm, suggesting that seasonal vertical migration in C. gracilis occurs. In terms of both frequency and number, earthworms were the most important prey items encountered, thus suggesting a specialized diet in C. gracilis. We found Trematoda and Nematoda parasites in low numbers and at low prevalence.